Laser curing of thermosetting powder coatings: A detailed investigation

Curing of thermosetting powder coating is conventionally done in a convecti on or infrared oven. Powders requiring 10-15 min at cure temperature in a c onvection oven reportedly cure within 2-4 min in an TR oven. It has been sh own that it is possible to achieve a much faster curing by using a cw CO2 l aser. Laser curing has been studied as a function of laser intensity, laser beam size, and interaction time on different substrates. A comparison of l aser curing with convection oven curing has been done by studying the resul ts of time-temperature profile, ac impedance, differential scanning calorim etry, and other characterization techniques. The mechanism of laser beam in teraction with the powder layer has also been discussed. (C) 1999 Laser Ins titute of America. [S1042-346X(99)00206-5].